Reins separates the owner’s funds from the account an agent can use. The default policy names three distinct XRPL accounts. Each has a different job.
Vault
The owner holds the vault keys. The vault does not delegate authority to the agent. It can issue capped refill Checks addressed to the allowance account.
Keep vault keys outside the agent runtime. Compromise of an owner device or owner key is outside the agent allowance boundary.
Allowance
The allowance account holds funds reachable by the agent. It delegates only the transaction types configured in the policy.
The ledger enforces that delegation and the account’s balance constraints. Permission Delegation limits transaction types, not the amount of every payment. Toolkit checks can narrow the supported workflow, but they do not turn a delegated type into an on-ledger per-payment cap.
Agent
The agent acts as a delegate of the allowance account. It holds a fee float rather than the owner’s treasury keys.
Reins’ MCP tools can prepare transactions for this identity. Loading an agent signing key enables the submission path; leaving it out gives you an inspection and preparation workflow.
Refills are explicit exposure
A refill Check has a maximum amount and an expiration. These are properties the ledger evaluates. Creating or releasing more reachable funds changes the practical exposure.
When evaluating an allowance, consider its spendable balance, reserves, fees, outstanding objects, and reachable refills. Do not read budget.amount as a cap on all payments across a day.
period: 24h controls a refill Check’s lifetime. Reins does not currently ship an independent policy service that enforces rolling daily velocity.
Optional hardened topology
A policy can also name watchdog and agentKey accounts. They must appear together and be distinct from the other accounts. This topology configures the agent account with a 2-of-2 signer list and disables its master key.
The account topology exists in the alpha. The planned independent policy co-signer for per-payment caps, payee rules, and daily velocity is a separate feature and has not shipped. Do not enable a hardened setup without understanding the matching signing and watchdog flow.
Continue with policy configuration or the enforcement boundary. 